Yes, birds were on the wing, migrating our way in force. Skleney, naturalist at the Willowbrook Wildlife Center in Glen Ellyn, showed our bird walk group the radar map that proved it. Made with readings taken at 2 a.m., it showed the lower half of the eastern/central U.S. covered with blue dots representing concentrations of birds, like a northbound blue tide.

But our late spring meant that the trees here were only starting to leaf out. That meant fewer insects, which feed on the leaves. And that would presumably mean fewer migrating birds, which feed on insects.

"I wouldn't expect a whole lot, warbler-wise," Skleney told the binocular-toting gathering, which was large enough that he divided us into two groups.

But minutes after our group set out, people were calling out so many warbler sightings that it was hard — in my case impossible — to keep up.

"A Nashville!"

"Yellow warbler!"

"I've got a black-throated green warbler."

"Blackburnian!"

This last, from sharp-eyed 17-year-old Graham Deese — he and his younger brother are volunteers at Willowbrook who help lead bird walks — got my beginner's heart racing. I had seen pictures of the orange- and black-streaked Blackburnian — like a Hot Wheels car painted with flames, Skleney put it — and wanted to see the real thing.

However, it was a devilishly overcast morning, dulling the appearance of brightly-colored birds. Adding the fact that warblers are small and move fast, even the veteran birders were struggling.

"Oh, crap," sighed Joan Campbell, who leads bird walks at Lyman Woods, as the Blackburnian flitted off before she could get her binoculars on it.

I saw only a fraction of the birds others saw, even with such excellent directions as these from Deese: "The second peeling-bark tree, at the branch that comes in level with the main trunk of the first peeling-bark tree, then look up in the canopy."

But I finally saw that Blackburnian.

"Everyone got the Blackburnian?" Skleney called out. "OK, we can go home now."

We didn't, of course. Over the course of an hour and a half, we — and by "we," I mean "they" — saw 52 species, combining both groups' totals, including eight birds seen for the first time this season.

"This is the best day so far this year, no doubt about it," Skleney said happily. "I'm really kind of amazed."